Looking to unlock your iPhone, iPhone 3G, or iPhone 3GS? You’ve come to the right place.

Every iPhone sold in the United States is “locked” to AT&T. What does this mean? Wikipedia:

Most iPhones are sold with a SIM lock, which restricts the use of the phone to one particular carrier, a common practice with subsidized GSM phones. Unlike most GSM phones however, the phone cannot be officially unlocked by entering a code. The locked/unlocked state is maintained on Apple’s servers per IMEI and is set when the iPhone is activated.

While the iPhone was initially sold in the US only on the AT&T network with a SIM lock in place, various hackers have found methods to “unlock” the phone from a specific network. Although AT&T is the only authorized iPhone carrier in the United States, unlocked iPhones can be used with other carriers after unlocking.

You might have guessed that the iPhone-hacking community has managed to skirt this restriction. Well, they have, and it’s called “Unlocking”. It’s your only option if you want to use your iPhone with any US wireless service besides AT&T.

Disclaimer: Be very careful when attempting to unlock your iPhone! Unlocking your iPhone is much riskier in terms of whether your iPhone can become “bricked”. Proceed with caution and be sure to follow all steps carefully. Make sure you have the right firmware / baseband version before following the steps of a tutorial!

Unlock Original iPhone:

You can unlock your iPhone using QuickPWN - instructions here: How to Jailbreak/Unlock Your 1st Generation iPhone 2.2.1. This tutorial will unlock the original iPhone using QuickPWN, and then unlock your iPhone at the end of the process.

If you want to unlock the original iPhone 3.1.2 or iPhone 3.1.3, you will want to use this guide for redsn0w: Jailbreak, Activate and Unlock Original iPhone 2G 3.1.3 Firmware Using redsn0w [Windows/Mac] This guide will walk you through each step of first jailbreaking, then unlocking your original iPhone 3.1.2/3.1.3 with redsn0w.

Unlock iPhone 3G:

You can unlock your iPhone 3G using yellowsn0w - software brought to you by the iPhone Dev Team, creators of redsn0w. In order to unlock your iPhone 3G, you will need to update your iPhone to the 2.2 iOS, jailbreak it using QuickPWN, then unlock the iPhone 3G with yellowsn0w. Detailed instructions can be found here: iPhone 3G SIM Unlock Guide

Alternatively, you can unlock your iPhone 3G with ultrasn0w if you are on one of the newer firmwares. This guide assumes you have already jailbroken your iPhone 3G. If not, check the Jailbreak Software Selector page before proceeding with this guide. Once your iPhone 3G is jailbroken, use this guide to unlock it: How to Unlock iPhone 3G Using Ultrasn0w Note: This method is compatible with the newest iOS 4.

Unlock iPhone 3GS:

You can unlock your iPhone 3GS using ultrasn0w, which requires your iPhone 3GS to be previously jailbroken. If your iPhone 3GS is not jailbroken, use Jail-Break.net’s Jailbreak Software Selector page to determine how to jailbreak it. Once your iPhone 3GS is jailbroken, follow this guide: How to Unlock iPhone 3GS Using Ultrasn0w Note: This method works with iOS 4.